The popularization of digital still cameras in recent years has fostered expectations of ever cheaper cameras. There is thus a demand for reduction in the cost of imaging optical systems that are built into the cameras. The portability of digital still cameras is also a major issue. The size and weight of zoom lenses, as image-capturing lenses, have to be reduced in order to achieve smaller, thinner and lighter camera bodies.
To meet these demands, a zoom lens has been developed that comprises, in order from an object, a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having positive refractive power, wherein the first lens group comprises only two lenses by effectively arranging an aspherical lens as a negative lens in the first lens group (for instance, Japanese Laid-open Patent Publication No. 2005-84648(A)).